During a lecture a professor was talking about the potential that hydrogen has for exploding under certain conditions. Which was most likely the topic of the professor's lecture?

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

When the mercury level in a barometer decreases that atmospheric pressure has